Oxide Perovskite Nanodevices as a Monolithic Topological Superconductor Platform
Abstract
A new advancement is proposed in controlling superconductivity at the nanoscale by tuning electrostatic gate voltages. The key proposed enabler is the use of oxide perovskite single crystals as a monolithic quasi-2D system combining gate-tunability, superconductivity, and clean nanopatterning. The target geometry is a mesoscopic island coupled to a 2D electron gas by tunneling point contact. Tunneling spectroscopy and transport measurements in magnetic field will demonstrate that this system hosts all ingredients requiredto realize the Kitaev Chain Hamiltonian. Further dimensionality reduction from mesoscopic island to long and quasi-one-dimensional nanowire will be pursued to enable realization and detection of Majorana bound states.This proposal builds on nanofabrication technique development in the strontium titanate material system by the PI, culminating in a recent demonstration of ballistic superconducting transport in a simple quantum point contact geometry. This project will substantially increase superconducting oxide nanodevice complexity beyond the present state of the art. The central current challenge in Majorana device research is reducing disorder. Material and device imperfections not only obscure topological bound state signatures but produce remarkable imitations of such signatures from trivial origins. The proposed device realization in a monolithic gate-tunable superconductor is a plausible route towards transformational reduction in device disorder. Even at this early stage of development, the proposed oxide nanodevice platform exhibits remarkably competitive disorder metrics such as micron # scale mean free paths and clean ballistic conduction in simplified geometries. Further reduction of disorder is an important long-term goal for this research direction.Beyond the proposed target of topological superconductivity, oxide perovskites are a platform that is very rich in incompletely understood materials physics as well as unusual functionality. The proposed superconducting device development will thus broadly impact cryogenic microwave, acoustoelectric,and spintronic devices. This includes enabling new components for superconducting qubits and the circuit quantum electrodynamics toolbox. The distinctive long-term promise of this proposal is in creating quantum device platforms from monolithic materials, in which functional boundaries are defined not structurally, but electronically.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 24, 2024
- Source ID
- N000142412079
Entities
People
- Evgeny Mikheev
Organizations
- Office of Naval Research
- United States Navy
- University of Cincinnati